Method for a single guidelane, bidirectional, passenger carrying tramcar system
The invention is a method of coordinating the movement of a plurality of oppositely directed tramcars operating along a single guidelane. This includes positioning a plurality of fixed stop-boarding areas along the guidelane. By-pass lanes enabling oppositely moving tramcars to pass each other are located in association with at least some of the stop-boarding areas. A predetermined arrival time for each tramcar at each stop-boarding area is calculated such that oppositely moving pairs of tramcars approaching a common stop-boarding area will arrive at approximately the same time. A processor onboard each tramcar calculates the distance and time remaining to the next stop-boarding area. With a known time and distance remaining to the next stop-boarding area, each on-board processor adjusts the speed of the tramcar such that it arrives at approximately the predetermined arrival time.
The present invention relates to passenger-carrying transit systems which operate in a single guidelane dedicated only to the transit system and not shared with other vehicles; in which multiple passenger-carrying vehicles (hereinafter referred to as “tramcars”) operate in both directions along the single, dedicated guidelane; in which the movement of the multiple tramcars is coordinated such that oppositely moving tramcars only meet each other at a tram-stop boarding area, where passengers embark and debark the tramcars, and where a short bypass is provided in the guidelane enabling one tramcar to go around the other prior to, or after, passenger embarking and debarking is complete; in which the movement of the multiple tramcars is further coordinated such that oppositely moving tramcars always arrive at a mutual tram-stop boarding area at substantially the same moment; and in which this coordinated, synchronous arrival is maintained in spite of random delay events experienced by one or more of the tramcars within the system (caused, for example, by having to slow down or stop when other vehicles or pedestrians inadvertently encroach upon, or cross, the tramcar's guidelane.)
The principal benefit of the synchronous tramcar arrivals is a very high convenience level for system users. Without synchronous arrivals, passengers would board the first tramcar to arrive at any given tram-stop boarding area, but would then have to wait for the oncoming tramcar to also arrive before the car they had just boarded would be able to bypass and continue. This unpredictable waiting period would make the system feel inconvenient, and discourage ridership. Synchronous arrivals, in contrast, would make the system feel highly convenient and encourage ridership.
The above method of coordinating the movement of multiple, passenger-carrying tramcars in a single, dedicated guidelane is able to produce very high people-moving capacities for two reasons: First, since the tramcars do not share lane space with other traffic, they do not experience the delays of local traffic congestion. Second, at full capacity, tramcars arrive at the tram-stop boarding areas with very high frequency. While dual-guidelane systems can achieve equal people-moving capacity, the single guidelane method described has the following advantages: (1) capital costs are reduced since only a single guidelane need be constructed; (2) a smaller footprint or right-of-way is required since the method utilizes only one guidelane rather than two; (3) passengers are provided the convenience of being able to board a tramcar going in either direction from a single tram-stop boarding area;
Finally, the above method has a significant advantage over Automated People-Mover systems which, for reasons of public safety, must be elevated above, or otherwise separated from the possibility of pedestrian or vehicular intrusion into their guidelanes. In contrast, the above method—in which the tramcars are able to slow or stop in response to unpredicted, inadvertent pedestrian or vehicular guidelane encroachment—enables the system to operate safely on the same grade with, and in close proximity to, pedestrian and vehicular traffic.
DESCRIPTION OF THE PRIOR ARTIt is known from my prior U.S. Pat. Nos. 5,611,282 and 5,676,059, which are herein incorporated by reference, to coordinate the movement of multiple tramcars, moving in both directions along a single, dedicated guidelane, such that oppositely moving tramcars only meet each other at tram-stop boarding areas, and are further coordinated such that the oppositely moving tramcars always arrive at mutual tram-stop boarding areas at substantially the same moment. A short bypass in the guidelane or guidelane associated with each tramstop allows the tramcars to then bypass each other just prior to, or just after, passengers have embarked and debarked at the boarding area, thus enabling the tramcars in the system to (1) move continuously in their opposite directions without colliding and (2) ensuring the tramcars bypass each other without having to incur the delay of waiting for an oncoming tramcar to arrive. The method described in the referenced patents applied to both substantially linear guidelane configurations, in which the tramcars reverse direction at each end-stop, and loop configurations in which one set of tramcars moves continuously in one direction around the loop, and another set of tramcars moves continuously in the opposite direction.
In the referenced patents, however, the method of coordinating the movement of the tramcars requires a plurality of sensors along the guidelane which sense the location of the tramcars, the sensed tramcar locations then being communicated to a central processor which, in turn, communicates back to one or more of the tramcars, adjusting its speed, such that any two tramcars moving toward a mutual tram-stop boarding area would arrive at substantially the same moment. This method has the disadvantage of requiring multiple sensors along the guidelane which must be hardwired to a central processor, or which must utilize multiple wireless transmitters, and which also must distinguish between tramcars moving in opposite directions. It also has the disadvantage that the optimal spacing of sensors along the guidelane is dependent upon the tramcar speed, whereas the tramcar speed is variable.
An alternate method of sensing the location of the tramcars would be the utilization of GPS (Global Positioning System) technology. This, however, has two disadvantages: (1) GPS signals are often intermittent in urban areas with densely arrayed tall buildings—the kind of location this kind of people-mover is likely to be deployed—and (2) GPS accuracy is currently ±/−10 meters, which would cause tramcars to regularly experience at least some delay having to wait for an oncoming tramcar to arrive at a tram-stop bypass.
The prior art, then, does not show how to coordinate the synchronous arrivals of the oppositely moving tramcars without utilizing either guidelane sensors or utilizing GPS technology to communicate tramcar locations to a central processor.
The prior art also does not show how, once such a system begins operations, tramcars can be removed from the system to reduce operating costs during periods of low demand, or how tramcars can then be added back into the system during periods of peak demand, without interrupting the coordinated, synchronous arrivals of the system as a whole.
The prior art also does not show how such a system can maintain passenger-carrying operations, with synchronous arrivals at tram-stop boarding areas, if there is a mechanical breakdown or accident which blocks the guidelane for an extended period of time.
Finally, the prior art does not show how such a system, if operating in a city streetscape, could traverse signalized street intersections without each red-light incidence introducing a significant delay into the synchronous arrival sequence; or without signal pre-emption by the tramcars creating frequent and random traffic-signal cycling, causing delays and aggravation for the drivers of other vehicles, and possibly aggravating traffic congestion.
SUMMARY OF THE INVENTIONIt is an object of the present invention, then, to create a high capacity, highly convenient, passenger-carrying tramcar system which can operate safely in a single, dedicated guidelane, on-grade, in close proximity with vehicular and pedestrian traffic; and which eliminates the described disadvantages and deficiencies of the prior art.
With reference to this intention, an object of the present invention is to show a method of coordinating multiple tramcars, moving in opposite directions along a single, dedicated guidelane, such that oppositely moving tramcars arrive at mutual tram-stop bypass/boarding areas at substantially the same moment, without utilizing either location sensors along the guidelane, or GPS technology.
A further object of the invention is to show specifically how this “sensorless” method maintains tramcar coordination in the event that one or more tramcars are randomly delayed in their operation (for example, by vehicular or pedestrian activity temporarily encroaching on the guidelane).
A further object of the invention is to show specifically how this “sensorless” method can accommodate the dynamic adding of tramcars into the system (to accommodate peak-demand periods) or the dynamic removal of tramcars from the system (to reduce operating costs in periods of reduced demand) without disrupting the on-going synchronous arrivals within the system.
A further object of the invention is to show specifically how such a system, coordinated by this “sensorless” method, would maintain passenger-carrying services and synchronous arrivals in the event an accident or mechanical breakdown blocks the single, dedicated guidelane.
A final object of the invention is to show how such a system, coordinated by this “sensorless” method, can traverse signalized intersections, without being unduly delayed by red-lights and without causing frequent and random traffic-signal cycling.
The present invention will be more fully understood by reference to the following detailed description thereof when read in conjunction with the attached drawings, and wherein:
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If “Transmission ‘b’” indicates the traffic-light is red, the onboard processor will compare the time the light is going to cycle green with the time the tramcar will arrive at the intersection stopping point (traverse distance “Dred.”) at its present speed. If the light is going to cycle green before the tramcar arrives, the onboard processor takes no action; the tramcar continues at its present speed, the light cycles to green, and the tramcar proceeds through the intersection.
If, at its present speed, the tramcar is going to arrive at the intersection before the light is going to cycle green, the onboard processor calculates a slower speed which will cause the tramcar to arrive after the light cycles green, enabling it to proceed through the intersection. If this slower speed is equal to or greater than a predetermined minimum allowed speed, the onboard processor causes the motor controller 6 to slow the tramcar to the calculated speed.
If the calculated slower speed, described above, is less than a predetermined minimum allowed speed, the onboard processor causes the motor controller to slow the tramcar to the minimum allowed speed, calculates the no. of seconds it will then arrive before the light cycles green, and transmits a signal to the traffic-light controller 25, here depicted as “Transmission ‘c’”, instructing it to cycle green the appropriate number of seconds early. In this case the tramcar has pre-empted the signal, but has slowed to minimize the pre-emption.
If “Transmission ‘b’” indicates the traffic-light is green, the onboard processor will compare the time the light is going to cycle red with the time the tramcar will completely clear the opposite side of the intersection (traverse distance “Dgreen”) at its present speed. If the light is going to cycle red after the tramcar has cleared the intersection, the onboard processor takes no action; the tramcar continues at its present speed and proceeds through the intersection with the green light.
If, at its present speed, the tramcar is not going to clear the intersection before the light cycles red, the tramcar continues at its present speed, and the onboard processor transmits a signal to the traffic-light controller 25, depicted as “Transmission ‘c’”, instructing it to remain green for the additional number of seconds required for the tramcar to clear the intersection.
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While the foregoing specification and drawings describe the major components and method of operations of a preferred embodiment of the instant invention, it is to be understood that I do not intend to limit myself to the precise arrangements herein disclosed, since various details of arrangement, form and method may obviously be developed by anyone skilled in the art without departing from the basic principles and novel teachings of this invention and without sacrificing any of the advantages of the invention, and accordingly I intend to encompass all changes, variations, modifications and equivalents falling within the scope of the appended claims.
Claims
1. A method of coordinating the movement of a system of a plurality of oppositely directed tramcars operating along a single guidelane, comprising:
- (a) positioning a plurality of fixed stop-boarding areas along the guidelane;
- (b) locating corresponding by-pass lanes in association with at least some of the stop-boarding areas;
- (c) calculating a predetermined arrival time for each tramcar at each stop-boarding area, such that oppositely moving pairs of tramcars approaching a common stop-boarding area will arrive at approximately the same time;
- (d) utilizing a processor onboard each tramcar to calculate the distance remaining to the next stop-boarding area, and the time remaining until the predetermined arrival time at the next stop-boarding area;
- (e) utilizing a processor onboard each tramcar, with a known time and distance remaining to the next stop-boarding area, to adjust the speed of that tramcar, such that it will arrive at approximately the predetermined arrival time;
- (f) utilizing an on-board odometer to determine the distance each tramcar has traveled since leaving the previous stop-boarding area.
2. The method of claim 1, including directing one of the pair of tramcars having arrived at, or about to arrive at, a mutual stop-boarding area into a bypass lane, allowing the other of the pair of tramcars to continue along the guidelane, thus enabling the pair of tramcars to pass each other.
3. The method of claim 1, including utilizing an onboard odometer to determine the distance each tramcar has traveled since the commencement of operations.
4. The method of claim 1, including utilizing an onboard electronic clock to determine the amount of time elapsed since commencement of operations.
5. The method of claim 1, including utilizing an onboard electronic clock to determine the amount of time elapsed since leaving the previous stop-boarding area.
6. A method of coordinating the movement of a system of a plurality of oppositely directed tramcars operating along a single guidelane, comprising:
- (a) positioning a plurality of fixed stop-boarding areas along the guidelane;
- (b) locating corresponding by-pass lanes in association with at least some of the stop-boarding areas;
- (c) calculating a predetermined arrival time for each tramcar at each stop-boarding area, such that oppositely moving pairs of tramcars approaching a common stop-boarding area will arrive at approximately the same time;
- (d) utilizing a processor onboard each tramcar to calculate the distance remaining to the next stop-boarding area, and the time remaining until the predetermined arrival time at the next stop-boarding area;
- (e) utilizing a processor onboard each tramcar, with a known time and distance remaining to the next stop-boarding area, to adjust the speed of that tramcar, such that it will arrive at approximately the predetermined arrival time; and
- (f) utilizing an onboard governor to control tramcar acceleration and decelaration such that acceleration and deceleration occur at a predetermined rate.
7. The method of claim 1, including assigning a maximum allowable speed for tramcars in each guidelane segment between stop-boarding areas.
8. The method of claim 7, including utilizing an onboard processor to determine in which guidelane segment the tramcar is located and calculate the speed required to reach the next stop-boarding area at the predetermined time, and compare that calculated speed to the maximum allowable speed for the segment.
9. The method of claim 7, including utilizing an onboard processor to calculate the number of seconds late the tramcar will arrive at the next stop-boarding area if it accelerates to the maximum allowable speed, and an on-board transmitter to communicate the number of seconds it will be late to a central processor/transmitter.
10. The method of claim 7, including utilizing a central processor/transmitter to communicate a delayed arrival time to an onboard tramcar processor, causing that tramcar to decelerate to a speed such that the tramcar will arrive at a mutual stop-boarding area at approximately the same time as its opposing tramcar.
11. The method of claim 1, including utilizing a central processor/transmitter to calculate a system-wide shift in the predetermined arrival times for all tramcars at all stop-boarding areas, and communicating this shift to all onboard tramcar processors, causing all tramcars to alter speed to arrive at their next stop-boarding area at the new predetermined arrival times.
12. The method of claim 2, including commencing operations with tramcars pre-positioned at stop-boarding areas such that when they commence operations and, if necessary, make an initial bypass of another tramcar, there will be an odd number, and at least one, empty stop-boarding areas between each pair of opposing tramcars.
13. The method of claim 2, including removing tramcars from the system at a predetermined stop-boarding area according to a predetermined sequence, such that the tramcars remaining will continue to have at least one—and always an odd number—of empty stop-boarding areas between any two opposing pairs of tramcars.
14. The method of claim 13, including adding tramcars back into the system according to a predetermined sequence, such that there will continue to be at least one—and always an odd number—of empty stop-boarding areas between any two opposing pairs of tramcars.
15. The method of claim 13, including utilizing a central processor/transmitter to calculate the schedule of arrival times at each stop-boarding area for a tramcar being added into the system, and to communicate this schedule of arrival times to the onboard processor in the said tramcar.
16. The method of claim 1, including bifurcating the system into a plurality of subsystems.
17. The method of claim 16, including utilizing a central processor/transmitter communicating to all the tramcars operating in the system that the system is to be bifurcated.
18. The method of claim 16, including utilizing a central processor/transmitter to determine the end-stop-boarding areas of the new subsystems on each side of the bifurcation point, and to calculate a new schedule of arrival times for each tramcar at each stop-boarding area for each subsystem; and communicate this information data to the onboard processor of each respective tramcar.
19. The method of claim 16, including utilizing a central processor/transmitter to establish a new start-up time for the new subsystems on each side of the bifurcation point, and communicating that start-up time to the tramcars in each system.
20. The method of claim 16, including utilizing a central processor/transmitter to establish a new start-up time to rejoin the bifurcated subsystems into a single system.
21. The method of claim 20, including utilizing the central processor/transmitter to calculate a new schedule of arrival times for each tramcar at each stop-boarding area, and communicate the schedule of arrival times to the onboard processor for each respective tramcar.
22. The method of claim 1, including utilizing a communicator at each stop-boarding area which communicates to waiting passengers the time remaining until the next tramcar arrives.
23. The method of claim 22, including utilizing a central processor/transmitter to calculate the time until the next tramcar arrives at each stop-boarding area, and communicates that time to the communicator at each respective stop-boarding area, causing the information to be conveyed.
24. The method of claim 22, including utilizing a central processor/transmitter to communicate to each stop-boarding area communicator that the system is to be bifurcated, and cause the communicator to convey the new end-stop-boarding areas on each side of the bifurcation point, and the next arrival time for each tramcar at each stop-boarding area.
25. The method of claim 1, including predetermining a minimum dwell-time each tramcar will dwell at a stop-boarding area.
26. The method of claim 1, including predetermining the maximum dwell-time each tramcar will dwell at a stop-boarding area.
27. The method of claim 1, including utilizing driver operated tramcars with driver controls.
28. The method of claim 27, wherein the driver controls comprise an actuator such that when said actuator is engaged, the tramcar accelerates at a predetermined rate of acceleration to a speed calculated by the onboard processor; and when the actuator is disengaged, the tramcar decelerates, and continues to decelerate, at a predetermined rate of deceleration until a full stop is reached.
29. The method of claim 28, including utilizing further driver controls comprising a brake pedal such that when the brake pedal is engaged, tramcar brakes are applied commensurate with the pressure on the pedal applied by the driver; and such that if the driver applies a “panic” pressure, tramcar brakes are applied in a predetermined sequence of pressures to optimize safety.
30. The method of claim 1, including utilizing tramcars which operate on fixed rails, causing the tramcars to follow the path of the rails.
31. The method of claim 1, including utilizing tramcars with a terrestrial guide steering means which follows a terrestrial guide, or target, located in or on the surface of the guidelane.
32. The method of claim 31, in which the terrestrial guide steering means comprises an optical sensor located on the tramcar which causes the tramcar to follow an optical guide target located in or on the surface of the guidelane.
33. The method of claim 31 in which the terrestrial guide steering means comprises a magnetic sensor located on the tramcar which causes the tramcar to follow a magnetic guide target located in or one the surface of the guidelane.
34. The method of claim 31 in which the terrestrial guide steering means comprises an electromagnetic sensor located on the tramcar which causes the tramcar to follow an electromagnetic guide target located in or one the surface of the guidelane.
35. The method of claim 1, including utilizing tramcars which are bidirectional, capable of reversing direction at an end stop-boarding area.
36. The method of claim 35, including providing driver controls in driver cockpits at each end of the tramcar, enabling the driver to control the tramcar from either cockpit.
37. The method of claim 36, including utilizing conventional driver steering means, acceleration and braking control, in at least one of the driver cockpits, such that the tramcar can be driven out of the guidelane to a remote storage or maintenance facility.
38. The method of claim 1, in which a traffic light controller at a signalized intersection includes a transceiver, and the processor on board each tramcar communicates with the transceiver to determine when the traffic light is going to cycle such that, when necessary, the on board processor preempts the traffic light, causing the controller to modify its cycle, enabling the tramcar to enter and clear the intersection without having to stop.
39. The method of claim 38, in which the processor on board a tramcar approaching a red traffic light, causes the tramcar to decelerate to a speed such that the traffic light will change to green during its normal cycle before the tramcar arrives at the intersection, thus avoiding the need to preempt the traffic light.
40. The method of claim 38, in which there is a predetermined minimum speed the on board processor will allow a tramcar to decelerate to in order to avoid preempting a traffic light.
41. The method of claim 38, in which the processor an board a tramcar approaching a green traffic light which is about to change to red, causes the traffic light controller to maintain the green light until the tramcar has safely entered and cleared the intersection.
5611282 | March 18, 1997 | Alt |
5676059 | October 14, 1997 | Alt |
20030137435 | July 24, 2003 | Haddad et al. |
Type: Grant
Filed: Jun 14, 2004
Date of Patent: Aug 1, 2006
Patent Publication Number: 20050274277
Inventor: John D. Alt (Annapolis, MD)
Primary Examiner: S. Joseph Morano
Assistant Examiner: Robert J. McCarry, Jr.
Attorney: Arthur Schwartz
Application Number: 10/867,141
International Classification: B61J 3/00 (20060101); B61C 11/00 (20060101);